Use Document > Attributes > Document Code Reservation to reserve a range of document codes. Any user can apply or remove these reservations, but reserved document codes cannot be used until the reservation is removed. For instance, you might be expecting certain documents to be submitted by a subcontractor. You can therefore reserve a range of document code numbers for these documents, remove the reservation when they arrive and apply these codes to the documents. Reserved numbers must lie in the ranges allowed by the ProjectWise administrator, if allow restrictions have been applied.